Liquid-Solid-Solution Assembly of CoFe2O4/Graphene Nanocomposite as a High-Performance Lithium-Ion Battery Anode

- Crumpled CoFe2O4@graphene composite with uniform CoFe2O4 nanoparticles intimately anchored on graphene sheets was fabricated.
- The novel fabrication strategy: liquid-solid-solution strategy where the CoFe2O4 are nucleation and controlled growth at the oil/water interface.
- High reversible specific capacity of 1102 mAh g−1 after 100 cycles and high rate capability of 410 mAh g−1 within 230 s charging.

CoFe2O4/graphene composites were fabricated via a novel one-pot liquid-solid-solution (LSS) hydrothermal process. Through ions electrostatic adsorption onto graphene sheets and oil microemulsion encapsulation, CoFe2O4 nanoparticles can be uniformly anchored on crumpled graphene sheets without aggregation, and the size distribution of CoFe2O4 particles can be controlled by the microemulsion shell in the range of 50-100 nm. With the synergistic effect between CoFe2O4 and graphene, the CoFe2O4/graphene hybrid exhibits a high reversible specific capacity of 1102 mAh g−1 at 0.2 A g−1 after 100 cycles, and a good cycling stability as well. Moreover, the composite has good rate capability. The specific capacity can reach a high value of 410 mAh g−1 even under a high current density of 6.4 A g−1 (corresponds to a charge time of ∼230 s), indicating its promising application as an anode material for lithium ion batteries.

CoFe2O4/rGO composites are fabricated via a liquid-solid-solution assemble strategy with a well controlled CoFe2O4 size, the composite exhibits a high rate performance for lithium ion batteries anode.135